In 2008, Greszczyszyn earned a spot on the North American Cup Circuit and moved to Calgary to train full-time.

After competing for three years in North America, he earned a spot on the Europa Cup team and finished second overall.

The 2012–13 season was his first year on the Canadian national team; he finished third overall on the Intercontinental Cup circuit.

Dave is now a physical education teacher at North Trail High School in Calgary, Alberta which opened in 2023.

He played rugby at Brock University, and obtained a Masters of Teaching degree in Australia.